Labour has invited Housing Minister Phil Heatley to Christchurch to meet families living in desperate conditions after he told Parliament the city faced housing "challenges", not a crisis.
Heatley this week said Labour "might like to drum up the idea that there is a crisis".
"The reality is that there are housing challenges in Christchurch."
Housing New Zealand recognised those challenges and was rebuilding damaged houses, upgrading its stock and looking at building up to another 350 houses, he said.
However, local welfare agencies have insisted there is a crisis and are backed by Labour after Wigram MP Megan Woods and housing spokeswoman Annette King spent time with some of the city's most vulnerable people.
King said they visited a family of five being charged $300 a week to live in a freezing and mouldy caravan on a relative's property.
There were up to four families living in single houses because they had nowhere else to live.
"Because they are not seen, the Government says it doesn't happen."
More than 500 people had serious housing problems in Christchurch, she said.
"Yet Mr Heatley doesn't think it's a problem."
Woods yesterday wrote to the minister inviting him to visit her electorate.
"To call this a challenge, not a crisis, is an absolute abdication of his responsibility as minister. I'm happy to show him what a crisis looks like."
The current flu outbreak in Christchurch was caused by the cold and damp conditions people were living in, she said.
Earthquake Recovery Minister Gerry Brownlee last month denied there were massive rent rises in Christchurch, and has also denied there is a housing crisis.
Heatley has said there would be no Government intervention in the rental market because the solution was to build more houses.
Hornby Presbyterian Church's the Rev Hamish Galloway said average rents in Hornby had risen from $280 to $360.
"For low-income families, that's really difficult. The biggest areas of stress we are coming across are people who are having their rental tenancies come to an end and having to find new places."
The Government needed to take the issue seriously, he said. Its refusal to intervene in the rental market was philosophically driven because National supported the free market.
"Surely, when you're in an exceptional situation you can make laws and rules to protect the poorest of the poor."